The effects of DSP has entered every phase of our lives, from singing greeting cards to CD players and cell phones to medical x-ray analysis. Without DSP, there would be no Internet. In recent years, every aspect of engineering and science has been influenced by DSP because of the ubiquitous desktop computer and readily available signal processing software. This book provides engineers and scientists, who are relative beginners to DSP, their best opportunity to learn the basic mathematical and practical-engineering aspects of the burgeoning field of DSP. The book strikes the right balance of mathematical level, and practical engineering guidance, making it accessible to the beginner without dumbing down the topic of DSP. This edition of Understanding Digital Signal Processing will continue bridging the gap between DSP theory and practice. The presentation of additional quadrature processing material makes the book more relevant, and useful, to DSP practitioners in the burgeoning fields of digital communications and wireless networking systems. The new digital filtering material covers modern filter design techniques not covered in our competitor's books. Finally, the popular 'Digital Signal Processing Tricks' material will be expanded to further aid working DSP engineers solve their day-to-day signal processing problems as they design and build commercial products and aerospace systems.